In a new twist of the European migration crisis, officials in Brussels offered Turkey £2.3 billion and visa-free travel if it clamps down on the number of refugees making their way into Europe through its borders.

But a prominent German politician warned EU leaders may have robbed Peter to pay Paul, shutting off one influx but opening up the continent to 80 million Turkish citizens.Johannes Singhammer, vice-president of the Bundestag said there are “serious considerations” about the prospective visa-free regime, because it would open “a gateway for further immigration and a flow of refugees to Germany.”

He said that German consulates in Turkey are already issuing a staggering 200,000 visas a year for free travel in the Schengen zone and that number is now set to explode when the agreement comes into force in October.Mr Singhammer said migrants from war-torn Syria or Iraq could add to the influx, but also migrants from Turkey itself, saying the domestic conflict with the Kurds “has a vast potential to create new reasons [for those persecuted] to flee.”

German chancellor Angela Merkel has come under fire for her so-called open door policy to refugees and has insisted the answer to the migrant crisis is not to simply close European borders.

As reported by the Telegraph, the European Union are ignoring a demographic time bomb: a recent rush into the EU by migrants, including millions of Muslims, will change the continent beyond recognition over the next two decades, and almost no policy-makers are talking about it.

The numbers are startling. Only 3.2 per cent of Spain's population was foreign-born in 1998. In 2007 it was 13.4 per cent. Europe's Muslim population has more than doubled in the past 30 years and will have doubled again by 2015. In Brussels, the top seven baby boys' names recently were Mohamed, Adam, Rayan, Ayoub, Mehdi, Amine and Hamza.

Europe's low white birth rate, coupled with faster multiplying migrants, will change fundamentally what we take to mean by European culture and society. The altered population mix has far-reaching implications for education, housing, welfare, labour, the arts and everything in between. It could have a critical impact on foreign policy: a study was submitted to the US Air Force on how America's relationship with Europe might evolve. Yet EU officials admit that these issues are not receiving the attention they deserve.

The growing Muslim population is of particular interest. This is not because Muslims are the only immigrants coming into the EU in large numbers; there are plenty of entrants from all points of the compass. But Muslims represent a particular set of issues beyond the fact that atrocities have been committed in the West in the name of Islam.

How dramatic are the population changes? Everyone is aware that certain neighbourhoods of certain cities in Europe are becoming more Muslim, and that the change is gathering pace. But raw details are hard to come by as the data is sensitive: many countries in the EU do not collect population statistics by religion. EU numbers on general immigration tell a story on their own. In the latter years of the 20th century, the 27 countries of the EU attracted half a million more people a year than left. "Since 2002, however," the latest EU report says, "net migration into the EU has roughly tripled to between 1.6 million and two million people per year." Muslims, who are a hugely diverse group, have so far shown little inclination to organise politically on lines of race or religion. But that does not mean their voices are being ignored. Germany started to reform its voting laws 10 years ago, granting certain franchise rights to the large Turkish population. It would be odd if that did not alter the country's stance on Turkey's application to join the EU. Mr Perkowski's study says: "Faced with rapidly growing, disenfranchised and increasingly politically empowered Muslim populations within the borders of some of its oldest and strongest allies, the US could be faced with ever stronger challenges to its Middle East foreign policies."

Demography will force politicians to confront these issues sooner rather than later. Recently, some have started to nudge the debate along. Angel Gurría, the OECD secretary-general, said in June: "Migration is not a tap that can be turned on and off at will. We need fair and effective migration and integration policies; policies that work and adjust to both good economic times and bad ones."